winy68

Ive been reading some of the existing threads on engine oil selection. It seems that a lot of people are using 5w-40. Even the dealer was using 5w-40 on my car. Also most online shops that sell oil change kits (blaupart, ECS, europa, etc) only sell kits with 5w-30 or 5w-40 oil.

My owners manual for my 05 4.2 states that 0w-30 should be used, but if it is not available 5w-30 or 5w-40 can also be used. as long as they conform to the VW 502 00 spec.

I took a look at bob's the oil guy's site to get a better understanding of oil, but my head started to spin after a couple minutes.

Why arent most of us Audi enthusiasts using 0w-30? - With the exception of Mishar, (who I believe mentioned in a post that he uses 0w-30)

Why do you suppose most shops aren't selling 0w-30? (some do carry 0w-30 but they dont seem to conform to the 502 spec)

My 05 A8L has about 110,000 miles and I driving mostly in a warm to hot climate (california high desert). Can anyone give an opinion on the best oil for my car and any ideas on why 0w-30 doesn't seem to be used that often?


thanks

Mister Bally

Simple for me; 5W-40 is a bit heavier than 0W-30 or 0W-40 depending on ambient temperatures. I feel the heavier oil will contribute to a longer lasting engine. I keep my vehicles for a long time. And I put a lot of miles on them.

uberwgn

Winy, the 502.00 standard contains a minimum HT/HS value. Any oil that meets the 502.00 standard will be thick enough.

richard-tx

Ihave been told that the Liquimoly brand syth oils are superior as they are a pure synthetic oil. What is being labelled synth here is the states can contain up to 20% dino oil.

the_duke

Liquimoly is good stuff. Name brand oil here in the states if labeled full synthetic is full synthetic. There are a lot of off brand oils now days though. I'm a big fan of Rotella T6 even though it's not 502 rated.

mishar

Oil flow is the most important component of engine lubrication. In 0W30 or 0W40 "0" marks cold oil viscosity. 30 or 40 hot oil viscosity. Cold start is critical moment for all engines. Oil that is viscous (heavy, tick) when it is cold provides poor lubrication at that critical moment. So "0W" is better than "5W" for all climates but especially cold morning starts. Hot engine in north of Canada and south of Mexico have very similar temperature, around 90°C. So 30 is viscous enough even in a very hot climate.

That said we should use 0W30 or 0W40 as our engines are older and bearing clearances a bit bigger.

Jack88

I have seen more than once people buying synthetic blends, which are a mixture of conventional and synthetic oils, not realizing it's not a suitable substitute for engines requiring full synthetic. Often times companies will try to promote the blend with the word synthetic quite prominent, so be careful if you see a surprisingly cheap synthetic. Odds are, you'll look closer and see the word blend in there.

MP4.2+6.0

Here's an odd one. I know of it since when I first got my 2006 the dealer didn't have the manuals--required as part of CPO. They handed me a set of 2005 manuals, and later got the 2006's.

Well, 2005 version says the one spec as mentioned here, but 2006 version focuses on 5W40 w/ the others being alternates. 2006 manuals are clear on complying to 502 spec. But nothing changed in the motor. Two or three theories:Big picture, if I am in moderate to hot regions (like even here in coastal CA), I tend toward the 0W40. In a commonly cool or colder area or if I were doing two changes a year timed to seasons, 0W30 in cool/cold months. As an engine ages and burns oil, you may need to shift away from the "0" spec oils anyway as I did with my older 4.2. It used to burn oil, and for that one which had an internal engine issue, more so when cold. Frankly, Audi dealers in the 1980's in the Bay Area used to use 20W50 Castrol as standard fill, so there is some latitude here. It's a balance of fuel economy, engine wear (esp. cold as Misha mentions) and oil burning if any.

Rhouse181

There are benefits and trade-offs to everything. The wider the range between cold and hot viscosity, the more friction modifiers get added to the formulation which makes the oil more susceptible to viscosity degradation and volatility over longer change cycles. If you are located in Alaska, then hell yea I would use a 0W oil. But it's really not necessary for 95% of residents located in the US.

The trend towards lighter viscosity oils recommended by manufacturers are to provide fractional improvements in fuel efficiency statistics. Unfortunately, these statistics are what sells cars these days and it sometimes gets in the way of what's supported by the engineers. I'd stick with your run of the mill 5w40 Castrol full synthetic if you want to remain vw502 compliant. If you don't care about vw502 compliance, then Shell Rotella T6 5w40 is a far superior performing and less expensive alternative.

You are lucky you are pre-DI FSI change over, because I'd bore you more with oil volatility, lean stratified charge, and intake manifold carbon buildup!

TSHong

I agree and was running 0W40 Mobil 1 here in ATL. I found that Kendall's Euro Motoroil is VW 505.00,505.01, and 502.00 approved. It is also cost much less than Mobil 1 with my oil supplier so I have switched.

If I owned a FSI motor, I would drop to 5K oil changes for the carbon potential build up issues.